Git. C# tree way strategy for conflicted files

My big problem is that I want to generate .mine .their and .base version of conflict file and then feed them to customer's comparer. My app is a command line wrapper that execute git.exe with arguments. So I wanna try to extract requered files with

git show :1:dir1/file1.txt > dir1/file1.base.txt

git show :2:dir1/file1.txt > dir1/file1.mine.txt

git show :3:dir1/file1.txt > dir1/file1.theirs.txt

but for windows filepath should be specify another way

    string args = "show :1:\"dir1\\file1.txt\" > \"dir1\\file1.base.txt\" ";

and I got an error : "fatal: Path 'dir1\file1.txt' exist on disk, but not in the index". Ok, maybe it's because index of file store in UNIX format.

But, for UNIX format I get another error: "fatal:Path 'dir1\file1.txt' doesn not exist (neither on disk nor in the index)"

Please help me, I don't know what to do. Maybe there is another way to get these files.